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Diffstat (limited to 'libAACenc/src/transform.cpp')
| -rw-r--r-- | libAACenc/src/transform.cpp | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/libAACenc/src/transform.cpp b/libAACenc/src/transform.cpp new file mode 100644 index 0000000..99b8a6b --- /dev/null +++ b/libAACenc/src/transform.cpp @@ -0,0 +1,203 @@ +/***************************************************************************** + + (C) copyright Fraunhofer IIS (2001) + All Rights Reserved + + Please be advised that this software and/or program delivery is + Confidential Information of Fraunhofer and subject to and covered by the + + Fraunhofer IIS Software Evaluation Agreement + between Google Inc. and Fraunhofer + effective and in full force since March 1, 2012. + + You may use this software and/or program only under the terms and + conditions described in the above mentioned Fraunhofer IIS Software + Evaluation Agreement. Any other and/or further use requires a separate agreement. + + + $Id$ + Description: FDKaacLdEnc_MdctTransform480: + The module FDKaacLdEnc_MdctTransform will perform the MDCT. + The MDCT supports the sine window and + + the zero padded window. The algorithm of the MDCT + can be divided in Windowing, PreModulation, Fft and + PostModulation. + + This software and/or program is protected by copyright law and international + treaties. Any reproduction or distribution of this software and/or program, + or any portion of it, may result in severe civil and criminal penalties, and + will be prosecuted to the maximum extent possible under law. + +******************************************************************************/ + +#include "transform.h" + +#include "dct.h" +#include "psy_const.h" +#include "aacEnc_rom.h" +#include "FDK_tools_rom.h" + +INT FDKaacEnc_Transform_Real (const INT_PCM * pTimeData, + FIXP_DBL *RESTRICT mdctData, + const INT blockType, + const INT windowShape, + INT *prevWindowShape, + const INT frameLength, + INT *mdctData_e, + INT filterType + ,FIXP_DBL * RESTRICT overlapAddBuffer + ) +{ + const INT_PCM * RESTRICT timeData; + + INT i; + /* tl: transform length + fl: left window slope length + nl: left window slope offset + fr: right window slope length + nr: right window slope offset + See FDK_tools/doc/intern/mdct.tex for more detail. */ + int tl, fl, nl, fr, nr; + + const FIXP_WTP * RESTRICT pLeftWindowPart; + const FIXP_WTP * RESTRICT pRightWindowPart; + + /* + * MDCT scale: + * + 1: fMultDiv2() in windowing. + * + 1: Because of factor 1/2 in Princen-Bradley compliant windowed TDAC. + */ + *mdctData_e = 1+1; + + tl = frameLength; + timeData = pTimeData; + + switch( blockType ) { + case LONG_WINDOW: + { + int offset = (windowShape == LOL_WINDOW) ? ((frameLength * 3)>>2) : 0; + fl = frameLength - offset; + fr = frameLength - offset; + } + break; + case STOP_WINDOW: + fl = frameLength >> 3; + fr = frameLength; + break; + case START_WINDOW: /* or StopStartSequence */ + fl = frameLength; + fr = frameLength >> 3; + break; + case SHORT_WINDOW: + fl = fr = frameLength >> 3; + tl >>= 3; + timeData = pTimeData + 3*fl + (fl/2); + break; + default: + FDK_ASSERT(0); + return -1; + break; + } + + /* Taken from FDK_tools/src/mdct.cpp Derive NR and NL */ + nr = (tl - fr)>>1; + nl = (tl - fl)>>1; + + pLeftWindowPart = FDKgetWindowSlope(fl, *prevWindowShape); + pRightWindowPart = FDKgetWindowSlope(fr, windowShape); + + /* windowing */ + if (filterType != FB_ELD) + { + /* Left window slope offset */ + for (i=0; i<nl ; i++) + { +#if SAMPLE_BITS == DFRACT_BITS /* SPC_BITS and DFRACT_BITS should be equal. */ + mdctData[(tl/2)+i] = - (FIXP_DBL) timeData[tl-i-1] >> ( 1 ); +#else + mdctData[(tl/2)+i] = - (FIXP_DBL) timeData[tl-i-1] << (DFRACT_BITS - SAMPLE_BITS - 1); +#endif + } + /* Left window slope */ + for (i=0; i<fl/2; i++) + { + FIXP_DBL tmp0; + tmp0 = fMultDiv2((FIXP_PCM)timeData[i+nl], pLeftWindowPart[i].v.im); + mdctData[(tl/2)+i+nl] = fMultSubDiv2(tmp0, (FIXP_PCM)timeData[tl-nl-i-1], pLeftWindowPart[i].v.re); + } + + /* Right window slope offset */ + for(i=0; i<nr; i++) + { +#if SAMPLE_BITS == DFRACT_BITS /* This should be SPC_BITS instead of DFRACT_BITS. */ + mdctData[(tl/2)-1-i] = - (FIXP_DBL) timeData[tl+i] >> (1); +#else + mdctData[(tl/2)-1-i] = - (FIXP_DBL) timeData[tl+i] << (DFRACT_BITS - SAMPLE_BITS - 1); +#endif + } + /* Right window slope */ + for (i=0; i<fr/2; i++) + { + FIXP_DBL tmp1; + tmp1 = fMultDiv2((FIXP_PCM)timeData[tl+nr+i], pRightWindowPart[i].v.re); + mdctData[(tl/2)-nr-i-1] = -fMultAddDiv2(tmp1, (FIXP_PCM)timeData[(tl*2)-nr-i-1], pRightWindowPart[i].v.im); + } + } + + if (filterType == FB_ELD) + { + const FIXP_WTB *pWindowELD=NULL; + int i, N = frameLength, L = frameLength; + + if (frameLength == 512) { + pWindowELD = ELDAnalysis512; + } else { + pWindowELD = ELDAnalysis480; + } + + for(i=0;i<N/4;i++) + { + FIXP_DBL z0, outval; + + z0 = (fMult((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N/2-1-i])<< (WTS0-1)) + (fMult((FIXP_PCM)timeData[L+N*3/4+i], pWindowELD[N/2+i])<< (WTS0-1)); + + outval = (fMultDiv2((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N+N/2-1-i]) >> (-WTS1)); + outval += (fMultDiv2((FIXP_PCM)timeData[L+N*3/4+i], pWindowELD[N+N/2+i]) >> (-WTS1) ); + outval += (fMultDiv2(overlapAddBuffer[N/2+i], pWindowELD[2*N+i])>> (-WTS2-1)); + + overlapAddBuffer[N/2+i] = overlapAddBuffer[i]; + + overlapAddBuffer[i] = z0; + mdctData[i] = overlapAddBuffer[N/2+i] + (fMultDiv2(overlapAddBuffer[N+N/2-1-i], pWindowELD[2*N+N/2+i]) >> (-WTS2-1)); + + mdctData[N-1-i] = outval; + overlapAddBuffer[N+N/2-1-i] = outval; + } + + for(i=N/4;i<N/2;i++) + { + FIXP_DBL z0, outval; + + z0 = fMult((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N/2-1-i]) << (WTS0-1); + + outval = (fMultDiv2((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N+N/2-1-i]) >> (-WTS1)) ; + outval += (fMultDiv2(overlapAddBuffer[N/2+i], pWindowELD[2*N+i]) >> (-WTS2-1)); + + overlapAddBuffer[N/2+i] = overlapAddBuffer[i] + (fMult((FIXP_PCM)timeData[L-N/4+i], pWindowELD[N/2+i])<< (WTS0-1) ); + + overlapAddBuffer[i] = z0; + mdctData[i] = overlapAddBuffer[N/2+i] + (fMultDiv2(overlapAddBuffer[N+N/2-1-i], pWindowELD[2*N+N/2+i]) >> (-WTS2-1)); + + mdctData[N-1-i] = outval; + overlapAddBuffer[N+N/2-1-i] = outval; + } + } + + dct_IV(mdctData, tl, mdctData_e); + + *prevWindowShape = windowShape; + + return 0; +} + |